9dpo is very early to be testing. I did loads of early testing and never had convincing results that early in any of the 3 times I have conceived. Even first response is only 50% accurate or so at that stage. What sort of test did you use?
For best results test at 12dpo. Most of the good brands will work then.
if you know when you ovulated then regardless of pcos, a period should come within 16 days of ovulation. First response worked for me, faintly, at 11dpo this pregnancy. But try again on or after 12dpo if you are sure of your ovulation date. They usually tell the truth by that stage.